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Biomedical subjects

M Wells

Publications and source records attributed to M Wells.

At least 199 records · Page 11Linked to original sources
PubMed1985

Mucin histochemistry of cystitis glandularis and primary adenocarcinoma of the urinary bladder.

We describe the histochemical properties of mucin in three cases of cystitis glandularis affecting the urinary bladder. Of particular importance is the positive staining reaction that was obtained with the periodate borohydride/potassium hydroxide/PAS (PB/KOH/PAS) technique, indicating the presence of O-acetylated sialic acids. This reaction has been regarded as unique to the epithelial mucins in the normal terminal ileum and large intestine. Therefore, cystitis glandularis represents a true mucous metaplasia of large intestinal type. A case of primary adenovillous carcinoma of the bladder associated with cystitis glandularis also produced O-acetylated sialomucin, whereas a primary adenocarcinoma of urachal origin did not. The demonstration of O-acetylated sialic acid producing glandular epithelium in the bladder cannot be assumed to represent a metastasis from a colorectal cancer. The PB/KOH/PAS staining technique may provide a means of distinguishing between primary adenovillous and primary urachal carcinoma of the bladder.

Adenocarcinoma↗
PubMed1984

Spiral (uteroplacental) arteries of the human placental bed show the presence of amniotic basement membrane antigens.

The spiral arteries of the placental bed lose clearly recognizable arterial features early in pregnancy because of their invasion by extravillous trophoblast. Extensive structural alterations take place in the walls of invaded arteries, their walls containing an amorphous acidophilic "fibrinoid" matrix in which endovascular trophoblast is embedded. Such spiral arteries examined by immunofluorescence techniques in placental bed biopsy specimens obtained at cesarean section show a characteristic pattern of reaction with antisera to epithelial basement membrane amniotic antigens. These antisera have been previously demonstrated to react with the basement membrane of human amnion and of ectodermally derived epithelium such as breast ducts and skin. Interstitial trophoblast usually does not contain these antigens, and it is postulated that, following vascular invasion, endovascular trophoblast produces amniotic antigens to establish its presence. This may be of importance in maintaining the structural integrity of spiral arteries and thereby adequate maternal blood flow to the fetal-placental unit.

Amnion↗
PubMed1984

Adaptation to jejunoileal bypass promotes experimental colorectal carcinogenesis.

The co-carcinogenic potential of 85 per cent jejunoileal bypass (JIB) was tested in male Sprague-Dawley rats (n = 81) given 6 preliminary injections of the selective intestinal carcinogen azoxymethane (total dose 90 mg/kg). Controls had sham JIB. Colorectal adaptation was studied 30 weeks postoperatively in rats given injections of vehicle alone. JIB caused 17-33 per cent increments in colonic length, weight and crypt depth; crypt cell production rate was more than doubled (P less than 0.01). Despite lowering body weight by 27 per cent, JIB increased the median number of colorectal tumours per rat from 3 to 8 (P less than 0.01). The findings suggest that evidence of hyperplasia and dysplasia should be sought in patients receiving subtotal jejunoileal bypass for obesity.

Adaptation, Physiological↗
PubMed1984

Müllerian clear cell carcinofibroma of the uterine corpus.

A case of homologous Müllerian clear cell carcinofibroma occurring in the uterine corpus of a 71-year-old woman is described. The classification, histogenesis and possible biological behaviour of this unique tumour are briefly discussed.

Aged↗
PubMed1984

Class I antigens of the major histocompatibility complex on cytotrophoblast of the human placental basal plate.

The lack of class I antigens of the major histocompatibility complex (MHC) on syncytiotrophoblast has been proposed as an explanation for the survival of the allogeneic fetus. These antigens, however, have recently been detected on nonvillous trophoblastic columns of the early human placenta. By using a combination of immunofluorescence techniques to identify trophoblast, we have studied transplantation antigens of the cytotrophoblastic shell present in the basal plate of normal full-term human placentae. With the use of two different monoclonal antibodies to a common determinant of HLA (clones W6/32 and 61D2), it was shown that this subset of trophoblast does express class 1 MHC antigens. However, while these cells reacted uniformly with W6/32, only rare reactivity with 61D2 was found. Reactivity of polyclonal antisera to beta 2-microglobulin correlated with that seen using W6/32. These results are similar to those recently observed in a subset of trophoblast of the amniochorion to which the term "metatrophoblast" has been given.

Antibodies, Monoclonal↗
PubMed1984

Immunological studies of human placentae: complement components in pre-eclamptic chorionic villi.

Forty human placentae were studied by immunofluorescence for the presence of complement (C) components C1q, C4, C3d, C6 and C9 with the use of characterized antisera. The tissues were grouped as control placentae from 20 normal pregnancies and 20 from cases of pre-eclampsia (PE): the PE samples were sub-grouped as being obtained from patients with mild or severe PE. All of the C components studied were found in the same distribution for test and control samples, but statistical analysis of each pattern of distribution revealed that the deposition of C1q, C3d and C9 were increased in PE as compared to normal tissues. This impression was strengthened by the finding that the deposition of these C components was further increased when chorionic villus immunopathology was compared between mild and severe PE. These data indicate that immunological mechanisms are operating in PE chorionic villi, and they suggest that, among other mechanisms, immune processes may be operative in the pathophysiology of this clinical disease, and that more studies along these lines are in order to rule either in or out this possibility.

Adolescent↗
PubMed1983

A new technique for the study of temporal bone pathology.

A new technique for the study of the temporal bone at autopsy is presented in which thin slices of the fixed bone are prepared on a special cutting machine which preserves the configuration of the delicate anatomical structures. Selected areas are then processed for light microscopy. There is thus opportunity for gross examination, only a short period for immersion in acid for decalcification if required, and special histological procedures may also be carried out. The method is quick and technically easier than serial sectioning and storage of the smaller numbers of sections from each case is less of a problem. Temporal bones which have been perfused through the perilymph within 3 h of death may also be cut in the same way in order to allow removal of samples of membranous labyrinth for surface preparation or electron microscopy, avoiding the need for drilling to reach the membranous labyrinth, and being quicker and less damaging.

Histological Techniques↗
PubMed1983

The pathology of meconium ileus equivalent.

A case of meconium ileus equivalent in a 25-year-old woman with cystic fibrosis is reported and the pathology of this condition is described. On gross examination the lumen of the terminal ileum was completely obstructed by a mass of inspissated faecal material with a putty-like consistency. The principal microscopic findings were plugging of the mucosal crypts with mucoid secretion, distention of goblet cells and the presence of a thick layer of mucus, admixed with faecal material, adherent to the mucosal surface. Mucin histochemistry demonstrated sulphomucin in the terminal ileum, although acidic mucins in the normal small intestine are almost exclusively non-sulphated.

Adult↗
PubMed1982

The treatment of nocturnal enuresis in institutionalized retarded adults.

This study employed a procedure for nocturnal enuresis with seven adult female residents of a state institutional ward for the retarded. The procedure included: positive reinforcement for remaining continent for gradually lengthened time periods; nightly awakenings at the beginning of their wetting periods, and a restriction of fluids before bedtime. There was a reduction for all residents in the monthly mean wetting frequency, from a baseline average of 6.6 to 0 by the end of treatment. All residents became accident-free after 12 months of treatment and had no relapse in a 1 yr follow-up. In a 4 yr follow-up, the four residents remaining in the institution were still accident-free. While the procedure required a comparatively long period, it had the advantages of low cost, and a low relapse rate.

Adult↗
PubMed1982

Congenital abnormalities of the ear in perinatal deaths.

A study of temporal bone history was carried out on 15 cases of perinatal deaths. Specimens included cases of general abortion, abortion due to rubella, still births and postnatal deaths. In one case that survived for 7 years with congenital hearing loss the clinical and audiological findings were available as well as the temporal bone histology. Ten of the cases had abnormal stapes and 5 had a cochlear duct abnormality ranging from absence of one turn to complete distortion of the normal configuration. The possible role of maternal factors in the production of these abnormalities is discussed.

Child, Preschool↗
PubMed1982

Intestinal adaptation and experimental carcinogenesis after partial colectomy. Increased tumour yields are confined to the anastomosis.

Small-bowel resection enhances experimental colorectal carcinogenesis, probably by stimulating epithelial cell proliferation. The possibility that similar mechanisms might explain metachronous large-bowel cancers in man was tested in Sprague-Dawley rats submitted to partial colectomy before or after a five-week course of azoxymethane (total dose 50 mg/kg). The timing of operation did not affect tumour yields at 40 weeks. Caecal resection augmented mucosal mass in the ileum and right colon but did not affect carcinogenesis. Right hemicolectomy only increased ileal segmental weight (by 22%); left hemicolectomy increased the protein and DNA contents of the residual right colon by 18-42%. Large-bowel tumours in 84 rats were distributed as follows: proximal colon 36, colonic anastomosis 51, distal colon 87, rectum 43. Consistent with this left-sided predominance, left hemicolectomy reduced the number of large-bowel tumours. A twofold increase in distal tumours after both transection and right hemicolectomy simply reflected the high incidence of anastomotic tumours. Furthermore, one rat given vehicle as opposed to carcinogen developed an invasive mucinous adenocarcinoma at the colorectal anastomosis, after left hemicolectomy. The large bowel shows limited adaptation to partial resection and is not at increased risk of carcinogenesis, except in the region of the suture line.

Adaptation, Physiological↗
PubMed1980

Squamous cell carcinoma of the middle ear.

The clinic features of 28 cases of squamous cell carcinoma of the middle ear are reviewed. Only one patient developed cervical lymph node metastasis and one radiological evidence of pulmonary metastasis. Fourteen of 23 patients (61%) died within 5 years after treatment from intracranial extension of the neoplasm. The pathological findings in three cases in which serially sectioned temporal bones were available are described. An important feature in each case was a penetration by tumour of the bony wall on the medial wall of the middle ear to infiltrate the carotid canal and b penetration by tumour of the thin layer of bone between the posterior mastoid air cells and the dura with subsequent invasion along the dura and into the internal auditory meatus. In one case the cochlea was infiltrated from the latter situation, but direct invasion of the cochlea from the middle ear was not observed. In view of the extensive infiltration that is probably already present at the time of diagnosis, radical surgical procedures are contraindicated.

Adult↗
PubMed1980

Antibiotic prophylaxis in ventricular shunt surgery. II. Antibiotic concentrations in cerebrospinal fluid.

Investigation of cerebrospinal fluid (CSF) antibiotic levels from patients operated upon under short-term prophylactic protocols for shunt insertions or revisions revealed low-level CSF penetration by nafcillin and virtually no methicillin activity. Nafcillin levels were not influenced by route of injection or CSF sampling time, but were inversely proportional to ventricular size. The authors recommend nafcillin over methicillin as the preferred prophylactic agent in shunt surgery. Although the 25 mg/kg preoperative dose may be adequate for reducing infection risk, higher dosages should be considered when the ventricles are markedly dilated.

Cerebrospinal Fluid Shunts↗
PubMed1980

Antibiotic prophylaxis in ventricular shunt surgery. I. Reduction of operative infection rates with methicillin.

Administration of prophylactic antibiotics is not a proven or universal practice in cerebrospinal fluid (CSF) shunt surgery although case and operative infection rates in hydrocephalic patients average 20 and 8%, respectively. In sequential series from 1969 through 1978 the authors achieved a reduction in case infection rates from 10.9 to 8.9% and in operative infections from 8 to 2.6% with the use of short-term prophylactic methicillin. Comparison of these results to those of other reported series supports the case for short-term prophylactic antibiotics in shunt surgery. Further reduction in shunt sepsis may be possible with the appropriate selection of other semisynthetic penicillins which achieve higher levels in CSF.

Bacterial Infections↗
PubMed1979

Needle biopsy under computerized tomographic control: a method for tissue diagnosis in intracranial lesions.

Thirteen patients with intracranial lesions were submitted to a twist drill needle biopsy under computerized tomographic (CT) control, with sedation and local anesthesia. (The patients' ages ranged from 12 to 81 years.) The final diagnoses were glioblastoma in 7 patients and 1 case each of anaplastic astrocytoma, low grade astrocytoma, thrombosed arteriovenous malformation, cerebral infarct, 3rd ventricular epidermoid, and degenerative disease of the brain. Definitive diagnosis was obtained in all but 2 patients with this technique. Appropriate therapy was subsequently instituted in 11 patients without further operation. Transiently increased weakness of the previously affected limbs was the only untoward effect (4 patients). Intracranial hematoma after this procedure was seen in 1 patient in this series, as detected by the postprocedure CT scan, but there was no change in the clinical course. All patients were treated with dexamethasone for 24 to 48 hours before and for several days after the procedure to avoid decompensation of intracranial dynamics because of edema. The procedure, including appropriate level CT scans of the lesion area, was performed in approximately 1 hour in all patients. (Neurosurgery, 5: 671--674, 1979).

Adolescent↗